This invention relates to fasteners of the type wherein two articles, or two parts of an article, are joined together, at least one of the joined articles or parts including an array of a plurality of fastening projections adapted to releasably inter-engage with the other article or part. In one aspect, the invention relates to such fasteners in which both components to be fastened include arrays of headed projections which can be simultaneously engaged with each other. In another aspect, the invention relates to an array of projections which may terminate in loops, or hooks, in the projections.
Typically, the array of projections is formed using a plurality of filaments which are joined with a backing material at spaced locations.
The art contains descriptions of fasteners including two articles, at least one of which includes an array of projections for providing fastener means. One such article comprises a woven fabric backing from which extend a plurality of headed projections adapted to join with loops of fiber projecting from another article, to effect the fastening. Such articles are produced by weaving two backing layers in parallel, closely spaced, relationship, with the filaments being woven therebetween. The filaments are then severed midway between the backing layers to form two brush-like halves, and the newly severed projecting filaments are heated to form heads on their terminal ends. These articles, however, are expensive to make because of the weaving required, and the woven backing does not hold the filaments as tightly as may be desired. Also, the fasteners cover essentially an entire surface of the substrate onto which they are fabricated.
Other of the art teaches embedding the projections of a longitudinally oriented polymeric filament material in a resinous polymeric bonding layer such that bight portions of the filament are physically embedded in the backing material. U.S. Pat. No. 4,290,174 Kalleberg is descriptive and illustrative of embedding the bight portions of the filaments into the backing material. Such embedding is also taught in 3,363,038 Billarant.
Illustrative of common methods of attaching filamentary material to a backing material is that shown in Kalleberg 4,290,174, wherein filaments are reciprocally pushed against the backing material at uniformly spaced intermittent locations, and wherein each locus of bonding a filament to the backing material requires a separate reciprocal pushing. Between each locus of bonding there is formed a loop in the material which becomes the structure from which the array of filament fasteners is eventually derived.
An alternate method of forming loops and subsequently providing for a backing material and bonding the loops to the backing material is disclosed in Billarant 3,363,038. The method of forming the loops is disclosed therein as comprising a complex arrangement of control members to push the filaments into grooves 94 in a forming wheel by means of bars 48 and counterbars 67. The filaments are then carried on bars 48 and counterbars 67 with subsequent extrusion of a polymeric backing material over the filaments to thereby bond a backing material to the filaments at the time that the backing material is formed into a sheet or film. Billarant teaches extensive camming apparatus, as well as a complex arrangement of filament feeding and forming apparatus which delivers the filaments to bars and counterbars in order to form the loops and hold their shape and position while the backing material is formed over the loops and subsequently solidified. Indeed counterbars 67 are retracted a distance from the filaments before extrusion of the backing material over the formed loops.
While there are a plurality of teachings in the art of methods for making the arrays of fasteners to which this invention relates, in each case the apparatus, or its method of use, is substantially complex, and in some cases requires large amounts of floor space and investment in equipment, as in the Billarant and Kalleberg patents.
It is an object of this invention to provide novel apparatus and improved methods for fabricating arrays of projecting fasteners. It is also an object of the invention to provide novel fastener combinations and novel articles of manufacture.
It is a specific object of the invention to provide a novel apparatus and novel methods of fabricating arrays of fasteners which function in a manner similar to arrays conventionally known.